Protractor



Jan. 22, 1929. 1,699,619

w. MuENcH PROTRAC'IOR ts-Sheet 1 y Filed April 9, 1925 /55 BY Mgr/5R Mu-NCH.

ATTORNEY.

Jan. 22, 1929. 1,699,619

W. MUENCH PRoTRAcToB Filed April 9, 1925 s sheets-sneer 2 WML 52 INVENTOR. MIJ/5R MUENCH.

A TTORNE Y.

Jan. 22, 1929. 1,699,619

w. MUENCH PRoTRAcToR Filed April 9, 1925 s Sheets-sheet 5 l N VEN TOR.

ML rE/e Mu/VCH. BY

A TTORNE Y.

Patented Jan. 22, 1929.

y yU'Nrrsu sTATl-:s

PATENT yOFFICE.

WALTER IMIUIENCH, OF BROOKLYN, NEW YORK.

PBOTRACTOR.

Application meg April 9, 1925. serial No. 21,892

This invention relates to protractors `and more particularly to what I term a direct, reading protractor in which any angle be` tween zero and ninety degrees may be determined.

One of the objects of my invention is to provide a protractor in the form-of a right angle triangle embodying a ninety degree sector in which the body of the said'instru'- ment is stamped out in units of live or ten degrees or other convenient multiples 'of ninety degrees when considered in relation,

with a graduated ninety degree circular scale of the protractor.

To enable others skilled in the art to fully comprehend the underlying features of my.

invention that they may embody the same in the various modifications in structure and relation contemplated, drawings depicting a' preferred form have been annexed as a p art of this disclosure and in such drawlngs, slmilar reference characters denote corresponding parts throughout all the views, of which, Figure 1 isa view ofthe triangle protractor constructed in, accordance with my 1nvention.

Figure 1a is a sectional view through the squaring plug shown in Figure 1.

Figure 2 is a modified form of the invention showinga protractor stamped out in units of ten degrees.

Figure 2a is an end view of Figure 2.

Figure 3 lis a modified form of triangle,

protractor, similar to thatJ shown by 'Fig-I ure 1. Figure 4 is a modified form of protractor similar to that shown by Figure 2.

Figure 5 is a still further modified form of protractor, similar to thatshown by Figure 4. Referring now to the drawings, wherein like reference charactersdesignate coresponding parts throughout the several views,`5 designates in its entirety, the right angle tri angle protra'ctor and sector protractor, whichas shown in Figure l1, is provided with the edges 7, 8, said edges being extension lines to the edges 13, 1,4, respectively. The extreme ends 9,10*, are cutat an angle to align with the 45 degree. side l11, .which of course, is the hypotenuse of the triangle above referred to.

extend. In this The main body of the instrument is stamped out as indicatedby numeral 12, the vertical edge 13 and the base edge 14 being in alignment lwith the respective edges 8, 7, above referred to. The point 13a is the vertex 55 from which the degree lines of the pr'otractor type of combined triangle andprotractor, there are four squaring plugs 15, a sectional View of one of said plugs being shown by Figure 1a. Each plug consists 60 of an externally threaded bushing 16, permanently secured to the protractorl body, preferably by welding. .The bushing is split as indicated at 17 to a distance of one-third its length. cap 18, internally threaded as at 19, lits over the bushing 16, said cap belng provided with a cylindrical, solid, central shank 20,.wl1ich can be adjusted upwardly or downwardly by the action of the screw thread. By reason of the split portion 17, the upper end of the bushing will have a slight tension 0n the inside thread of the cap, thereby keeping the shank 20 in its lowered or raised fixed position as desired. The position of the bushing 16 is, ofcourse, A'such 75 that the edges 7, 14, and the edges 8, 13, are tangential to the shank 20.

The protractor shown in Figure 1 lis especially vdesigned .for use-by toolmakers, machinists, instrument makers, carpenters and various' other trade mechanics. Inthe case of a toolmaker, for instance, a certain piece of work requiring the laying out for drilling, milling or perhaps filing to an angle from a l given pointplet it be assumed that in Figure 18,21: designates the steel block and that on the lower right'hand edge is the point froml which certain degree lines would have to be plotted-on top of the steel block gv. In order to set the protractor for this. operation, it 90 would simply be necessary to screw the cap 18 down on the bushing 16 so that the shank 20 will protrude underneath the protractor disc for .the length of approximately onequarter of an inch.v The to'p and bottom 95 shank 20 of the squaring plug must both rest against the side of the steel'block and so it' is quite vevident that by the use of the protractor as above set forth, the vertex can-.be

brought into perfect alignment with any I point on the right hand edge of the steel block w. The bushed shan'ks, being positioned on the edges 7, 14, seeFigure 1, can then be brought into contact with the front edge of the steel block a or on either edge thereof depending of course, entirely on the nature of the work to be plotted or from the point from which the work is being measured. In the same manner, the protractor may be used on any side of the steel block and entirely about this piece of work. Were it necessary to plot the degree lines on the top surface of the steel block m from a point, say, eX- actly in the 4center from all fourv sides and it is desired to use the same protractor, it is quite obvious that the Shanks extending beneath `the surface of the protractor must now be withdrawn, which necessitates threading the cap 18 upward instead of downward on the bushing 16 until each shank 2O is iush with the bottom surface of the said protractor. It therefore, is not necessary to entirely withdraw the shank 20 from the bushing 16. When the Shanks are thus adjusted the vprotractor can Ithen be shifted so that the vertex 13 may be set at .the central point of the steel block as mentioned above to plot the desired degree lines. It will thus be seen that the squaring plugs on the protractor are, under certain conditions, very important for plotting degrees accuratelyon surfaces of the work. The instrument is provided with four squaring plugs, each having v a bushingwhich 1s permanently fastened for reasons ofaccuracy. There are two plugs on each side and while the instrument can be used on the front side only, yet can be swung so that it will fit at right angles into any position, which is relative to a vertical or horizontal line.

The main body of the protractor is stamped out into units, each of said units being a multiple of five degrees. This is what might be termed a five degree scale so that there are eighteen units between zero and ninety degrees. Each unitconsists of a lstaggered edge and when considered in connection with-the scale 21, provides four consecutive degrees that maybe quickly found or determined at any point on the scale. -The opposite or longer side of each unit, represents an angle which is a multiple of five degrees. In this' manner it will be seen that when accomplishing work involving unusual measurements where 1t 1s deslred to quickly ascertaln and draw a line without computations, the particular degree of angle may be determined either from the zero or ninety degree /point on the scale 21 which coincides with the staggered lines ofeach unit above referred to, 0r the individual may work from the units and check back to the scale.

Referring now to Figure 2 of the drawings, the instrument is in the form of a sector protractor, wherein the triangle feature` is eliminated. y The main body of the instrument is stamped outas indicated at 23.I The edge 10a is in alignment with the edge 10b on the extension 8a. The edges 10 and 10b are bevelled merely to produce a very fine4 edge for drawing lines in laying out problems or to align this ne edge to certain fixed points when reading off degrees on drawings, and

,so forth. On account of the bevelled edge 10a and 10b, this protractor can be used on the front side only. The bevelled edge 5a of the protractor disc is simply to conform to the appearance of the instrument. The point 7a is the vertex of the sector. Theedge 35 must be regarded as the base of the instrument.

In this form of the invention, a ninety degree scale, as indicated at 24, is shown similar to that shown in connection with Figure 1. In this type of instrument I also provide a series of units blocked out 1nv multiples of ten degrees so that nine of such units of ten degrees each, are present. The sides ofeach unit consist of a staggered edge broken by five consecutive lines of one degree dierence. In other words, any degree between one and live may be quickly determined alon one side of each unit. The opposite edge of unit is similarly cut so as to provide a staggered edge consisting of five connected lines,

for instance, each of which differs by one degree.. Considering each unit it will thus be;

seen that itconsists of a ten degree scale which coincides with the graduated scale 24. In the same manner, it will be readily observed that any degree between zero and ninety degrees may be quickly determined by referring to the scale 24 to one of the units or by a simple addition or substraction, the desired degree may be quickly found by working in the unit numbered and the accuracy may be checked up by referring back to the scale 24. This bevelled vprotractor' requires to be made individually in sets of two, one for left hand use and one for right hand use. `In

each

Figure 3 of the drawings, the triangle proon the' work. The sta-n1 ed out portion 28 permits of the drawing o a continuation line from the edge 29, the latter being formed by the'cut out space 30. The point 29"L is the vertex'of the sector protractor as well as of the triangle. Figure 4 is a further modified type line.

' modified form of of setor protractor somewhat similar to Figure 2. This form of the invention shows the cut out space 31 is provided, as in the other forms, to produce the edge 32 which correspondingly is in alignment with the edge 33 of the extension 8b. The main body of the protractor is stamped out in units of five degrees as indicated'at 34 and similar to the units as described in connection with Figure 1. However, the base 35i of the protractor, as in Figures 2 and 3, constitutes the zero point reading in one direction and the ninety degree point when reading in the opposite direction. The graduated scale, of"

course, is also provided for the obvious purpose and the reasons. heretofore given. The point 31a is the vertex'of the sector protractor.

Reference may now be had to Figure in which I have departed somewhat from the general staggered structure `of degree edges, n

` prlsmg an instrument having which permitted an`unlimited use in both laying out or reading oif of every single degree In Figure 5, in which both the triangle ndprotractor Afeatureis again defined as in Figure 1, and Figure 3, there is shown a protractor in so faras only every fifth and tenth degree line is produced as an edge in the protractor disc by the stamping out of the body of theinstrument. The long drawn edges numbered at lthe top closely resemble the long unit edges in Figure 3. The use of this protractor, is of course, limited in consequence of the spaces between the edges of every second to fourthvv and sixth to ninth degree..

For the purpose of laying off degree lines which are fractions of one degree, the protractor as shown in Figures 1, 2, 3 and 4 are provided with'locating holes 2, in which the pins of a vernier attachment fit, said attachment reading in units of one minute.

In the various protractors, each unit of five or ten degrees Ais numbered so that it is only necessary to countoi'I on the staggered edges, the degree desired without having to consult the graduated scale. For that reason the sector'scale can be left ofil on all protractors, as

in Figure 5, for instance. lIt is merely in conformity "with the custom that protractors, as shown in Figures 1 to 4 inclusive, be provided with degree graduations. 'For 4a summary remark, it is indicated that wherever the mchanical limits and features permitted it, in the different designs of my novel protractor, the numeration of the staggered degree edges and the' sectorial graduation is'provided on both the front and the back of the instrument. As this is the casein the designs shown in Figures 3, 4 and 5, if the instrument shown in Figures 3 and 4, for instance,'wereturned over from left to right, considering the vertical edge as if stationary, as in the leaves of a book, taking the position of the rotractor in Figure 5 and se making it possib e to draw degree lines or to read them off. fItlis evident v along the arc of a circle, degree scalevmarked thereon and correspond- 'arranged that the protractors shown in Figures 3, 4 and 5 can be fitted into any sector of an assumed circle by shifting or turning.

While I have illustrated and described my the details of construction or otherwise altering the arrangement of the correlated parts without departing from the vspirit of the invention or the scope of the appended claims.

The protractors shown 1n Figures 2 lto 5 inclusive are best suited for use by draftsmen, mechanical, electrical and civil engineers and by architects and contractors.

Having thus described my invention, what I claim as new and desire to secure by United States Letters Patent isz- 1. A combined triangle and protractor coma plurality of contiguous units cut out of the body thereof and having a ninety ing with said units, certain of the edges of each of the units being in radial -alignment with predetermined degree marks on the scale, there being a cutout in one corner of said protractor, the edges of which are in alignment with the 'end marks of saidscale respectively.

2. A protractor comprising an instrument havinga plurality of contiguous units cut out of the body thereof and having a ninety degree scale marked thereon to correspond with said units, the outer adjacent edges of each of said units constituting a difference of one degree in the scale and said units having points in alignment with the said ninety degree scale and the opposite edge of each of said units being radially cut to a predetermined degree.

3. A combination triangle and protractor lll() comprising an instrument having a plurality V of contiguous units cut out of the body thereof, and having 'a ninety degree scale marked thereon, in .alignment with predetermined angles as indicated by the said ninety degree scale, and

squaring plugs located along two sides of said instrument .in alignment with the ends of said scale.

4. In a protractor, a-sheet of material having a scale of angles thereon, there being portions cut out of said sheet at least one edge of each portion being of step-like formation whose radial risers align with predetermined angles as indicated by said scale. l

5. A combined triangle and protractor comprising asheet of material having a scale ofv angles thereon, there bein portions cut out 0f said sheet at least oneed);

the edges of each of said units being e of each portion being of step-like formation whose radial risers align with predetermined angles asindicated by said scale and a plurality of plugs along the'edge of said instrumeli 13o arranged to den e a linel passing through a predetermined unit on said scale.

combination triangle and protractor comprising a sheet of metal having a scale of 5 angles thereon, there of said sheet,I at least one being of step-like edge of each portion formation, the radial risers being portions cut out of which align with predetermined angles as indicated by said scale, and the opposite edges ofeach portion with other predetermined angles of the scale.

n testimony whereof I affix my signature.

WALTER MENCH. [14.5.]

being arranged to align 10 

